The NCI Director has challenged the scientific community to utilize existing and developing technologies to generate comprehensive profiles of molecular alterations in human tumors in order to define clinically relevant molecular tumor "signatures". In this project, we will pursue comprehensive studies of gene and protein expression in colorectal cancer. Colorectal cancer is a major cause of cancer morbidity and mortality in the western world, with about 140,000 new cases and 56,000 deaths annually in the U.S. Like other common epithelial cancers, its development is complex and a full accounting of its causes and pathogenesis remain elusive. The accumulation of mutations in proto- oncogenes and tumor suppresser genes contributes to the initiation of adenomatous lesions and their progression to carcinoma. In spite of the progress in cancer genetics, enormous work remains. An ongoing research project at the University of Michigan is entitled "Molecular Epidemiology of Colorectal Cancer (MECC)." The MECC project is a population-based, case-control study examining genetic sequence variation and environmental factors in colorectal cancer development. In this collaborative study, 2100 incident colorectal cases will be identified. In addition to collection of normal and tumor tissue, peripheral blood and serum are collected and stored on each case. Detailed histopathological studies are performed and epidemiologic risk factor information is obtained. Furthermore and of great importance for the work proposed here, clinical follow-up of patients entered into the MECC study is assured, and data on time to cancer recurrence and survival will be obtained. For the studies in this proposal, 480 colorectal cases and 20 normal mucosa specimens form the MECC study will be selected for the protein and gene expression analyses, with the principal selection criterion being that the cancer invaded through all layers of the bowel wall at the time of diagnosis, but distant metastases were absent (stages II and III). The study will include equal numbers of patients with stage II and III disease, where regional lymph node metastases or extension beyond contiguous tissues are absent in the former and present in the latter. A critical issue in stage II and III colon cancer is to define features which predict cancer recurrence and death. Therefore, a principal goal of our study will be to identify gene and protein markers which are associated with cancer recurrence and death in the 480 patients. In addition, the large body of clinical, histopathological, and epidemiological data to be collected in the MECC study will allow us to address the relationship of particular expression patterns to specific clinical and histopathological features as well as dietary and environmental factors.